JPH05283301A - Solid-state electrolytic capacitor - Google Patents

Abstract

PURPOSE:To provide a solid-state electrolytic capacitor which can surely be shielded from outer air of a solid-state electrolytic layer, secure a space to contain the solid-state electrolytic layer and the like without being affected by the working precision of an anode, and maintain stable electric characteristics with the manufacturing process simplified. CONSTITUTION:This capacitor is L-shaped in cross section and comprises a plurality of anodes 2, 4 made of oxide film layers, solid-state electrolytic layers 12, 14, and conductive layers 15, 16 generated one after another on the inner wall surface, which anodes are stuck. It also comprises a cathode 18 installed along with a conductive adhesive 17 in a space formed by enclosure of the anode, an encapsulating member (package 2) coating the outer surface of the anode, and outer terminals (anode terminals 24, cathode terminals 26) extracted from the encapsulating member which is formed integral or electrically connected with the anode or the cathode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor using a solid electrolyte such as an organic conductive polymer.

[0002]

2. Description of the Related Art Conventionally, as a chip-type capacitor using a solid electrolyte, there is one in which an oxide film layer, a solid electrolyte layer and a conductive layer are sequentially formed on the surface of a flat plate-shaped anode body. Since this capacitor deteriorates in characteristics when moisture or other impurities act on the solid electrolyte layer, it is necessary to adopt an exterior structure with excellent sealing performance. However, when resin is used for the packaging means, the sealing property of the packaging resin is incomplete, so that moisture in the air penetrates into the interior and causes deterioration of characteristics.

[0003]

Therefore, in order to strengthen the exterior structure, the structure of the anode body is devised, and for example, two plate-shaped anode bodies having a solid electrolyte layer formed on the surface thereof are used. , A structure in which each anode body is arranged on both sides of the cathode body, that is,
A sandwich structure has been proposed. The sandwich structure as described above has an advantage that the airtightness can be enhanced in cooperation with the exterior resin with which the surface of the anode body is coated, because the anode body itself forms a part of the exterior structure. In a further developed form of the capacitor using such an anode body, there is one in which a recess is provided on the surface of the anode body and a solid electrolyte layer or the like is formed on the bottom surface of this recess.
Such a solid electrolyte layer formed in the recess of the anode body can cover and hide the solid electrolyte layer with the anode body, and in particular, the anode body itself can also serve as a side surface exterior. Since the casing structure is composed of the anode body, a mechanically reinforced exterior structure can be obtained.

However, the use of such two anode bodies having a recess formed therein is to secure a space for accommodating the solid electrolyte layer and the cathode body in the recess, and moreover, two anode bodies are used. It will be necessary to bond them together without gaps. Therefore, in the case of joining the anode structure, processing accuracy of the order of 100 μm or less is required for processing the anode body, which is feasible, but in actual production, the yield is low on the production line, There were inconveniences such as high cost.

Therefore, according to the present invention, the solid electrolyte layer can be reliably shielded from the outside air, and the space for accommodating the solid electrolyte layer and the like can be secured without being affected by the processing accuracy of the anode body, and the manufacturing process can be simplified. In addition, it is an object of the present invention to provide a solid electrolytic capacitor that can maintain stable electrical characteristics for a long period of time.

[0006]

The solid electrolytic capacitor of the present invention has an L-shaped cross section, and has a plurality of anode bodies (in which an oxide film layer, a solid electrolyte layer and a conductive layer are sequentially formed on the inner wall surface). 2, 4) and a cathode body (18) installed together with a conductive adhesive (17) in a space formed by enclosing the anode body with the anode body.
And an exterior member covering the outer surface of the anode body (exterior body 2
2) and integrally formed with the anode body or the cathode body,
Alternatively, an external terminal (anode terminal 24, cathode terminal 26) drawn out from the exterior member electrically connected is provided.

[0007]

In this solid electrolytic capacitor, since the space for accommodating the conductive adhesive and the cathode terminal is formed by a plurality of L-shaped anode bodies, a recess is precisely formed in the anode body itself as in the conventional case. Since it is not necessary to process, it is possible to surely and easily form a necessary space by bonding a plurality of anode bodies.

Further, for example, by sticking two anode bodies together, the sealing property to the internal solid electrolyte layer and the like is secured, and the electrical characteristics are stabilized and the characteristics are maintained for a long period of time. Is possible.

[0009]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the solid electrolytic capacitor of the present invention, and FIGS. 2 and 3 show the manufacturing method thereof in the order of manufacturing steps. In this solid electrolytic capacitor,
In this embodiment, two anode bodies 2 and 4 (FIG. 2) are installed as a plurality of anode bodies having an L-shaped cross section, and the anode bodies 2 and 4 are bonded to each other to form one tubular body. To be done.
Such a tubular body has an advantage that the mechanical strength of the anode bodies 2 and 4 and the mechanical strength of the tubular body are considerably increased due to the stress distribution of the tubular body. The surface of the inner wall of each of the anode bodies 2 and 4 is subjected to surface enlargement treatment by etching, and the oxide film layers 8 and 10 are independently formed thereon by chemical conversion. On the upper surface of 10, solid electrolyte layers 12 and 14 made of a polymer film such as polypyrrole are formed by vapor phase polymerization, chemical polymerization or electrolytic polymerization. On the surfaces of the solid electrolyte layers 12 and 14, conductive layers 15 and 16 that form a substantial cathode together with the solid electrolyte layers 12 and 14 are formed. Therefore, an independent capacitor is formed in each of the anode bodies 2 and 4 with the solid electrolyte layers 12 and 14 as a unit.

Then, in the internal space formed by enclosing the anode bodies 2 and 4 by bonding the anode bodies 2 and 4,
A cathode 18 is installed while being filled with a conductive adhesive 17 that forms a conductor layer. This conductive adhesive 1
A cathode body 18 is electrically connected to each of the conductive layers 15 and 16 by means of 7, and a capacitor element in units of the solid electrolyte layers 12 and 14 is provided between the anode bodies 2 and 4 and the cathode body 18. It is parallelized. In addition, on the upper surface of the anode body 4,
An internal terminal 20 on the anode side corresponding to the cathode body 18 is connected.

The anode body 2 is covered with an exterior body 22 as an exterior member formed of a sealing resin such as acrylic resin or epoxy resin. In this embodiment, the exterior body 22 is formed into a rectangular parallelepiped. An anode terminal 24 is connected as an external terminal that is formed into a C-shape to the internal terminal 20 that is partially protruded from the side surface of the exterior body 22, and the cathode body 18 that is similarly protruded from the exterior body 22 is connected. Is connected to a cathode terminal 26 processed into substantially the same shape.
A part of the anode terminal 24 and the cathode terminal 26 is the exterior body 2.
It is installed on the lower surface side of 2 in a form capable of surface connection.

According to such a solid electrolytic capacitor,
The two anode bodies 2 and 4 are bonded together to form a cylindrical shape, and the internal space thereof is covered with the conductive adhesive 17 while hiding the solid electrolyte layers 12 and 14, and the anode body 2 Since the outer surface portion is covered with the exterior body 22, the capacity forming structure and the exterior structure can be simplified, and the size and the moisture resistance can be improved. Moreover, the solid electrolyte layer 1 independently formed on the inner wall surfaces of the anode bodies 2 and 4
The common use of the conductive adhesives 2 and 14 makes it possible to increase the capacity.

Next, a method of manufacturing this solid electrolytic capacitor will be described. As shown in FIG. 2A, a plurality of anode bodies 2, 4 having an L-shaped cross section are formed of a film-forming metal such as aluminum. It Each of the anode bodies 2 and 4 is processed into substantially the same shape, recesses 28 and 30 for joining the ends of the anode body 4 are formed in the edge portion of the anode body 2, and the back surface portion of the anode body 4 is A groove portion 32 is formed in accordance with the width and thickness of the internal terminal 20 for the purpose of installing the internal terminal 20 in its surface. To attach the anode bodies 2 and 4, the recesses 28 and 30
Is unnecessary, but by forming such recesses 28 and 30, positioning at the time of bonding is facilitated and the accuracy of the external dimensions of the bonded body of the anode bodies 2 and 4 is improved,
It is useful for improving work efficiency. Further, the groove 32 is
The internal terminal 20 can be included in the plane, which contributes to downsizing of the final product.

Next, as shown in FIG. 2B, the inner wall surfaces of the anode bodies 2 and 4 are subjected to an etching treatment and then a chemical conversion treatment to form oxide film layers 8 and 10, on which the oxide film layers 8 and 10 are formed. Gas phase polymerization,
The solid electrolyte layers 12 and 14 made of a polymer film such as polypyrrole are formed by chemical polymerization or electrolytic polymerization, and the conductive layers 15 and 16 are formed thereon. And the anode body 2
The cathode body 18 is installed on the upper surface of the conductive layer 15 on the side, and the internal terminal 20 is connected to the groove 32 of the anode body 4.

Next, as shown in FIG. 3C, the respective anode bodies 2 and 4 are bonded together with the solid electrolyte layers 12 and 14 inside with a conductive adhesive interposed therebetween to form a tubular body. Coalesce into. Then, the conductive adhesive 17 is poured into the internal space formed by the anode bodies 2 and 4 to form a conductor layer.

Next, as shown in FIG. 3D, the exterior body 22 is covered with a sealing resin so as to cover the anode bodies 2 and 4 and the cylindrical body.
Then, the cathode body 18 and the internal terminals 20 are projected from the wall surface of the exterior body 22. An anode terminal 24 is attached to the internal terminal 20, and a cathode terminal 26 is attached to the cathode body 18 by arrows a and b.
The solid electrolytic capacitor shown in FIG. 1 is obtained by fixing as shown in FIG.

In the above-mentioned embodiment, the outer casing 22 is formed by adhering the sealing resin. However, as shown in FIG. 4A, the outer casing 22 having a rectangular tube shape preformed with the sealing resin is used. May be. In this case, after the anode body 2 is inserted inside the tubular outer casing 22, as shown in FIG. 4B, the opening of the outer casing 2 is filled with the sealing resin 33 and sealed. By stopping, the anode body 2 can be sealed with the exterior body 22 and the sealing resin 33. Therefore, it is possible to realize the same exterior structure as that of the above embodiment.

Further, in the above-mentioned embodiment, the cathode body 18 and the internal terminal 20 are formed to have a uniform width. However, as shown in FIG. 5A, the portion connected to the solid electrolyte layer 12 and the anode body 4 are formed.
It is also possible to form a portion having a uniform outer diameter and a bar-shaped terminal portion 34, 36 having a uniform outer diameter on the end face portion.
When such rod-shaped terminal portions 34, 36 are formed,
As shown in FIG. 5B, after the anode body 2 is inserted into the outer casing 22 having a rectangular tubular shape, the opening of the outer casing 22 is sealed with lid plates 38 and 40 made of synthetic resin plates. By forming the airtight holding layers 42 and 44 of rubber or the like in the through holes of the rod-shaped terminal portions 34 and 36 of the lid plates 38 and 40,
The airtightness between the lid plates 38, 40 and the rod-shaped terminal portions 34, 36 can be maintained. In this case, the rod-shaped terminal portions 34, 36
Since the area of the contact portion with the lid plates 38 and 40 is reduced by forming the, the airtightness can be easily maintained. Also,
The lid plates 38, 40 and the exterior body 22 can be tightly adhered and fixed with an insulating adhesive or the like to integrate them and maintain airtightness.

If a part of the rod-shaped terminal portions 34, 36 is projected on the outer surface portions of the cover plates 38, 40,
As the anode terminal 24 and the cathode terminal 26 suitable for the rod-shaped terminals 34 and 36, for example, as shown in FIG. 6, an L-shaped anode in which a through hole 46 into which the rod-shaped terminal portions 34 and 36 can be inserted is formed in the standing wall portion. The terminal 24 and the cathode terminal 26 may be used. That is, the rod-shaped terminal portion 3 protruding from the lid plates 38 and 40
4, 36 are inserted into the through holes 46 to electrically connect the anode terminal 24 and the cathode terminal 26 by ultrasonic welding or a fixing means such as a conductive adhesive, and the lid plates 38, 40 and the anode terminal 2
4 and the standing wall portion of the cathode terminal 26 are closely attached and fixed.
As a result, a solid electrolytic capacitor as shown in FIG. 7 can be obtained. Therefore, in this solid electrolytic capacitor, the form of the external terminal is simplified, and the shape is in close contact with the outer surface portion of the exterior body 22, so that the product can be downsized.

Further, the rod-shaped terminal portion 3 is provided on the outer surface of the outer casing 22.
As shown in FIG. 8, by using the anode terminals 24 and 26 in which the pipe-shaped insertion portions 48 into which the rod-shaped terminals 34 and 36 can be inserted are formed, as shown in FIG. As shown in FIG. 9, the anode terminal 24 and the cathode terminal 26 as external terminals can be connected and fixed to the exterior body 22.

In the embodiment, the anode terminal 24 and the internal terminal 20, which are external terminals, and the cathode body 18 and the cathode terminal 26 are separate members, but they may be formed integrally or in the same member.

[0023]

As described above, according to the present invention,
An oxide film layer, a solid electrolyte layer, and a conductive layer are sequentially formed on the inner wall side surface of the plurality of anode bodies having an L-shaped cross section, and the internal space formed by bonding the anode bodies to each other has conductivity. After installing the adhesive and cathode body,
Since the outer surface of the anode body is covered with the exterior body, and the space for accommodating the conductive adhesive and the cathode body is formed by the anode body having an L-shaped cross section, the anode body itself can be precisely constructed as in the conventional case. Since it is not necessary to process the concave portion to secure the sealing property to the solid electrolyte layer inside, the desired characteristics can be easily maintained, the solid electrolyte layer can be reliably shielded from the outside air, and the processing accuracy of the anode body can be improved. It is possible to secure a space for accommodating the solid electrolyte layer and the like without being affected by the above, it is possible to simplify the manufacturing process, and it is possible to maintain stable electrical characteristics for a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a solid electrolytic capacitor of the present invention.

FIG. 2 is an exploded perspective view showing a method for manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 3 is a diagram showing a method of manufacturing the solid electrolytic capacitor shown in FIG.

4 is a vertical cross-sectional view showing another embodiment of the method for manufacturing the solid electrolytic capacitor shown in FIG.

FIG. 5 is a diagram showing another example of the capacitor element used in the solid electrolytic capacitor of the present invention.

6 is a perspective view showing an external terminal to be connected to the capacitor element shown in FIG.

7 is a longitudinal sectional view showing an embodiment of a solid electrolytic capacitor using the capacitor element shown in FIG.

FIG. 8 is a perspective view showing another embodiment of the external terminal used in the solid electrolytic capacitor.

9 is a partial cross-sectional view showing a solid electrolytic capacitor using the external terminal shown in FIG.

[Explanation of symbols]

 2, 4 Anode body 12, 14 Solid electrolyte layer 15, 16 Conductive layer 17 Conductive adhesive 18 Cathode body 22 Exterior body (exterior member) 24 Anode terminal (external terminal) 26 Cathode terminal (external terminal)

Claims (1)

[Claims] 1. A plurality of anode bodies each having an L-shaped cross section and having an inner wall surface on which an oxide film layer, a solid electrolyte layer, and a conductive layer are sequentially formed, and the anode body by bonding these anode bodies together. A cathode body installed together with a conductive adhesive in the space formed by the enclosure, an exterior member covering the outer surface of the anode body, and integrally formed with the anode body or the cathode body, or electrical A solid electrolytic capacitor, comprising: an external terminal that is connected to the external member and is drawn from the exterior member.